Several premises underlie Bill James’s new book, some of them radical, and it seems best to examine them individually.

1. It would be valuable to have a single number to represent the value of a player’s season. Well, sure. Wouldn’t it? People spend a lot of time rating things on a scale “from 1 to 10.” James proposes to do the same thing with baseball players, except it’s on a scale of 0 to about 50 or so (there are only about a dozen seasons in baseball history that rate higher than 50, including Barry Bonds’ 2001, which clocks in at 54). Each integer represents a third of a win, a “Win Share”. This would come in handy to resolve salary disputes, trade questions and bar arguments, for sure.

2. It is impossible to evaluate players by taking the average as a baseline. This too is true, and it has already been acknowledged by many other analysts who have introduced the concept of replacement value (the Baseball Prospectus boys with VORP, among others). James justly says that the value of a player is not in how far above the average he is but in the fact that he can play at this level at all. Poor Pete Palmer and his Linear Weights system take it on the chin for using average performance as a baseline, implying that a slightly-below average major league player has a value of less than zero.

3. The best way to analyze performance, particularly fielding, is to look at the team’s performance first, and then allocate it among the individual players. True again. For hitters it’s easy to separate individual hitting performance by ignoring situation-dependent statistics like RBI; for pitchers it’s a little more difficult; but fielders cannot be evaluated properly apart from the team.

4. The Win Shares of the players must add up to the wins of the team. Here we start to get into trouble. A team’s record can be predicted quite accurately by a Pythagorean formula, and in Win Shares James introduces a new formula, based on “marginal runs”, that is nearly as accurate. (In fact calculating Win Shares is just a matter of figuring a team’s marginal runs and allocating them among its members.) Some teams, however, significantly overperform or underperform, relative to the number of runs they score and allow. The 1984 New York Mets, who finished 90-72 despite being outscored by 24 runs, are a notorious example. It follows from James’s formulae that each marginal run a 1984 Met contributed was more valuable than each marginal run from an underperforming team, say, the 1984 Pittsburgh Pirates, who finished 75-87 despite outscoring their opponents by 48 runs. The adjustments here can range to 20% or more, dwarfing things like park factors. And it follows further that Hubie Brooks and Tony Pena both get 21 Win Shares, despite the fact that Pena outhit Brooks slightly and played a far more difficult defensive position far better. In other words, Brooks, according to James, was a better player in 1984 because his team was lucky. (All analysts agree–James himself may have been the first to say so–that when teams win a lot of close games, it’s mostly luck.) James defends such conclusions obliquely in an essay called The Snider/Mays Dilemma, as follows:

But in that case [of another overachieving team, the 1969 Mets], it seems OK, because, after all, we know what this team accomplished. We all understand that this isn’t the usual case. But in the Win Shares system, we follow the logic that whatever is accomplished by the team is credited to the players, wherever that leads us.

Now maybe we all know what the 1969 Mets accomplished, and won’t be thrown by Cleon Jones’s 30 Win Shares, but do we all know what the 1984 Pirates failed to accomplish, or will we take Tony Pena’s and Hubie Brooks’ 21 Win Shares apiece at face value? I am not certain that we should evaluate players relative to their teams’ expected instead of actual won-loss records, but I am certain that James can give a better defense of his method than he does here.

Smaller points: James says in The New Historical Baseball Abstract and elsewhere that closers are overrated and managers ought to ignore save situations and pitch their best relief pitchers when they are most valuable, i.e., in tied and one-run games. Couldn’t agree more. But in Win Shares he appears to ignore that argument, giving relievers arbitrary extra credit for saves to make his numbers work out. James also asserts that stopping the running game constitutes 50% of a catcher’s defense, although he admits that such an estimate is desperate work. This should be easy to add up, however, because we know, offensively, what stolen bases and caught stealings are worth. When I am feeling less lazy I will add up the alleged defensive contributions of some cannon-armed catcher like, say, Ivan Rodriguez, and see if they match up with what the offensive result of his SB/CS record would be worth.